DOREMY NCT02106312
ForLocalized translocation-confirmed myxoid liposarcoma, trunk or extremity, resectable
TL;DR5yr LRFS 97.4% after 36Gy/18fx preop RT in myxoid liposarcoma, wound complications 21%, median f/u 66.4mo.
The number that moves the dose decision is 97.4% 5yr LRFS at 36 Gy, matched to a 21% wound complication rate, with only 3% late G3. Dose is 2 Gy daily to 36 Gy preop, standard fractionation, so it transfers directly. This is a de-escalation read confined to translocation-confirmed MLS.
In localized translocation-confirmed myxoid liposarcoma of trunk or extremity going to resection, this supports 36 Gy preop as a discussed option in place of 50 Gy; it does not extend to other soft tissue sarcoma histologies, which were not enrolled.
36 Gy in 2 Gy daily fractions preop yielded 97.4% 5yr LRFS (95% CI 93.9-100%) at median 66.4 mo, with late G3 in only 3%. Standard fractionation, no special technique required, so the de-escalation from 50 Gy transfers directly in translocation-confirmed MLS.
The surgical read is the wound complication rate: 21% overall, 16% needing intervention, after preop RT at the reduced dose. Whether that beats 50 Gy is untested here (no comparator arm), but it is the number to weigh against reconstruction planning in trunk and extremity resections.
10 details 1 trial watching
Prospective, single-group, phase 2 nonrandomized trial across 9 tertiary sarcoma centers in Europe and the US. Enrollment ran November 2010 to May 2020; data analyzed January to December 2025. Median follow-up 66.4 months (IQR 48.8-87.5).
Adults with biopsy-proven and translocation-confirmed localized myxoid liposarcoma of the trunk or extremity. N=90, mean age 47 (SD 13.1), 50 (56%) male.
Preoperative RT to a reduced dose of 36 Gy in once-daily 2-Gy fractions, followed by resection. Delivered per protocol in all patients. Three pts (3%) did not proceed to surgery because of intercurrent metastatic disease.
Long-term local recurrence-free survival, progression-free survival, disease-specific survival, overall survival, and late toxic effects. No single stated primary endpoint for this long-term analysis.
Wound complications in 18 pts (21%), with 14 (16%) requiring intervention. Late toxic effects were grade 2 in 13 pts (15%) and grade 3 in 3 pts (3%).
The authors argue the long-term data support adopting 36 Gy as an option through shared decision-making, explicitly on the grounds that a phase 3 trial is impractical in a rare cancer. That is an argument about feasibility, not about evidence level, and the reader should price it as such.
Fourteen-year accrual window spans changing surgical and imaging practice, so the wound complication rate reflects a long era rather than current technique. Late toxicity is reported only as pooled grade counts, without organ or site attribution, which limits comparison against 50 Gy series.
| Endpoint | 5yr rate | 95% CI |
|---|---|---|
| Local recurrence-free survival | 97.4% | 93.9-100% |
| Progression-free survival | 81.0% | 72.6-89.4% |
| Disease-specific survival | 89.5% | 82.6-96.4% |
| Overall survival | 88.5% | 81.2-95.8% |
Single-arm phase 2, no randomised 50 Gy comparator; authors concede phase 3 impractical in a rare histology. Long f/u strengthens but does not replace randomisation.
- Wound complication rate vs 50 Gy in a randomised comparison n=300 · primary completion 2031-01 · prospective MLS registry, 36Gy vs 50Gy preop arms
- Whether dose reduction extends to other translocation-driven sarcoma subtypes
- Local control beyond 10 years
📚 Sources · 📄 1 paper
Abstract
The longer read
The case for reducing preoperative radiotherapy in myxoid liposarcoma has always rested on histology rather than on a general de-escalation argument, and this long-term readout is best judged on whether the biology holds up over time rather than on whether 97.4% is a large number. MLS is the soft tissue sarcoma subtype most consistently observed to respond to radiation, and the dose-reduction hypothesis was that a translocation-defined tumour with that sensitivity does not need the 50 Gy that was set empirically for soft tissue sarcoma as a whole. The relevant question for a reader is therefore not whether 36 Gy works, but whether local failures were merely deferred past the follow-up of the earlier reports. A median of 66.4 months, with an IQR reaching 87.5 months, is the part of this paper that carries real weight: local recurrence in extremity sarcoma is not typically a late event, and a 5-year LRFS of 97.4% with that much follow-up behind it substantially reduces the deferred-failure concern that a shorter report could not address.
What the design cannot do is quantify what was given up. There is no 50 Gy arm, so the comparison a clinician actually needs, whether local control at 36 Gy is non-inferior and whether the wound complication rate is genuinely lower, is made against external series rather than against a concurrent control. That matters in both directions. A 21% wound complication rate, with 16% requiring intervention, is not obviously low in absolute terms; its interpretation depends entirely on what the same surgeons at the same centres would have produced after 50 Gy. Accrual spanning November 2010 to May 2020 compounds this, because surgical technique, reconstruction, and imaging changed materially over that window, and an external historical comparator is drawn from a different era again.
The authors are candid that a phase 3 trial is impractical here, and they use that to argue for adoption through shared decision-making. That reasoning is about feasibility rather than about strength of evidence, and it should be read that way. Rarity makes randomisation hard; it does not convert a single-arm result into a randomised one. The practical consequence is that the confidence interval on LRFS, 93.9% to 100%, is the honest statement of what is known, and the lower bound is the number that should anchor a conversation with a patient rather than the point estimate.
Generalisability is the sharpest boundary. Eligibility required translocation confirmation, which is a stricter entry criterion than histological diagnosis alone, so the population is more homogeneous than a typical sarcoma cohort and the result cannot be carried to a tumour called myxoid liposarcoma on morphology without molecular confirmation. Trunk and extremity only, and localized only. Nothing here informs retroperitoneal disease, other liposarcoma subtypes, or the broader soft tissue sarcoma population where 50 Gy remains the reference. The result would be wrong if the responsiveness that motivates the dose reduction were less uniform across MLS than the translocation-defined entry criterion implies, or if the multicentre tertiary setting selected for surgical quality that a general practice cannot reproduce. Neither can be excluded from these data, and both are reasons to keep the discussion in a sarcoma centre.